Can Dogs Detect Carbon Monoxide in the Home?

Many people believe that dogs can detect carbon monoxide if there’s a leak. Is this true? The short answer is “no” — not the way people think. Although dogs have an incredible sense of smell, they can’t smell carbon monoxide. The reason for the confusion: Dogs can be affected by it before people can, due to their smaller size and higher metabolism. 

So, they may show early warning signs of carbon monoxide poisoning. But these signs aren't because they’re smelling it — they’re being affected by it. 

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What is carbon monoxide?

When fuels don’t burn completely, a colorless, odorless, tasteless gas called carbon monoxide is produced. This can result from things like:

• Gas furnaces

• Portable generators

• Grills that are used indoors (which is never a good idea)

• Cars running in garages

• Wood stoves

• Gas water heaters

• Fireplaces

Unfortunately, the fact that carbon monoxide has no smell presents quite a danger for people and animals, because you don’t know you’ve been exposed to it until you have symptoms.

Carbon monoxide detectors in homes

These devices are critical. Because carbon monoxide gives you no type of sensory warning, a detector is the only reliable way to know it’s present.

Best practices:

• Every sleeping area should have a detector installed near it.

• Every level of your home should have at least one carbon monoxide detector.

• Replace batteries regularly.

• Replace the devices according to the manufacturer's guidelines, which is usually every five to 10 years, or sooner, if needed.

Your dog, however, cannot detect this gas.

Related article

Dogs’ Sense of Smell: What Can Dogs Smell?

There’s a reason that sweet little nose is always pressed to the ground.

Why is carbon monoxide dangerous?

Your body needs oxygen, and carbon monoxide interferes with its ability to use it. Here’s what happens:

• Carbon monoxide binds to the hemoglobin in your red blood cells.

• It can do this more tightly than oxygen can.

• Therefore, it prevents oxygen from reaching the tissues that need it.

• The first organs to be affected are the brain and heart.

Even if carbon monoxide exposure is low over time, it can cause serious health problems. High-level exposure can be fatal to both pets and humans.

Can dogs smell carbon monoxide?

Despite popular belief, dogs cannot smell carbon monoxide. It has no odor molecules, so there’s nothing for a dog to detect. So, where does this myth come from?

When carbon monoxide is present, dogs may:

• React to other combustion-related smells

• React to changes in air quality

• Appear to be affected by carbon monoxide before people, by acting strangely

That’s where the confusion comes from. Their behavioral changes make people think dogs detect carbon monoxide, but they don’t.

How strong is a dog’s sense of smell?

It’s really impressive that, while people have around six million olfactory receptors, dogs surpass that by a wide margin. They have up to 300 million. Also, the area in a dog’s brain that’s devoted to smell is much larger.

Dogs can detect explosives, certain cancers, hypoglycemia, and subtle chemical compounds. But even with their fantastic sense of smell, they cannot detect odorless gases like carbon monoxide.

Related article

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A dog’s sense of smell can be 100,000 times stronger than a human—so when it’s bad, it’s bad.

How do dogs react to carbon monoxide exposure?

Since dogs can’t smell carbon monoxide, but react to it before people do, it’s essential to know what their symptoms are. Small dogs, senior dogs, and puppies will be the first to be affected. Why is that?

• Smaller body size

• Faster metabolism

• Faster respiratory rates

• Spending time closer to the floor, where carbon monoxide may concentrate.

So, while people are still feeling OK, your dog may begin to show symptoms.

Symptoms

Early symptoms of carbon monoxide poisoning in dogs can include:

• Vomiting

• Drooling

• Weakness

• Difficulty breathing

• Lethargy

• Pale or bright red gums

• Collapse

• Seizures

If not treated immediately, this poisoning can be fatal.

Behavioral changes

Often, the first clue that carbon monoxide may be present is not a physical sign, but behavioral changes in your pup. You might notice your dog:

• Pacing or restless

• Showing anxiety or agitation

• Whining or crying for no apparent reason

• Refusing to eat

• Trying to leave the house or hiding

Of course, these signs can indicate many other things, but if they come on suddenly, especially in more than one pet, this is a red flag to check for carbon monoxide.

How to protect your dog from carbon monoxide

The steps you take to protect your dog from carbon monoxide are also protecting you. Here’s what to do.

• Place carbon monoxide detectors on every level of your home.

• Do not run cars in enclosed garages.

• Do not use grills, camp stoves, or generators indoors.

• Have your heating system, including any fireplaces or chimneys, inspected annually.

• Don’t ignore a carbon monoxide alarm, even if your dog seems fine.

If the time comes that you suspect carbon monoxide exposure:

• Get everyone, including your pets, outside immediately.

• Call your gas company or emergency services.

• Get veterinary care for your dog, even if the symptoms are mild.

Dogs often require oxygen therapy, and their outcomes improve when treatment is sought early.

Bottom line

Dogs cannot smell carbon monoxide, even though that’s a long-standing myth. In fact, they can be affected by it more quickly than humans and may show early warning signs. These signs can be physical symptoms or behavioral changes, which often come first. That means your dog is not a reliable carbon monoxide detector.

If your dog acts strangely, lethargically, or sick, and the symptoms happen suddenly and across multiple pets at once, take this very seriously. This may have nothing to do with carbon monoxide, but you need to be sure.

FAQs

What signs does a dog show if there is carbon monoxide present?

A dog’s symptoms of being exposed to carbon monoxide may include: anxiety or restlessness, sudden lethargy, vomiting, trouble breathing, weakness, collapsing, or in severe cases, having seizures. There may be behavioral changes that you notice before there are any obvious physical symptoms.

Are dogs affected by carbon monoxide poisoning, and what are the symptoms? 

Yes, dogs are absolutely affected by carbon monoxide poisoning, just like people. In fact, they will often show signs before humans do. Symptoms can range from being mild (like fatigue or nausea) to severe (such as collapsing, having seizures, or even going into a coma).

If you suspect carbon monoxide exposure, treat it as a medical emergency for your pet and your entire household.

References‌

• Garcia, Alexis. “8 Signs Your Pet May Be Suffering from Carbon Monoxide Poisoning.” Product Care Recycling, 9 Oct. 2020. http://www.productcare.org/about/blog/pet-carbon-monoxide-poisoning. 

• Stadie, William C., and Kirby A. Martin. “THE ELIMINATION of CARBON MONOXIDE from the BLOOD.” Journal of Clinical Investigation, vol. 2, no. 1, 1 Oct. 1925, pp. 77–91, dm5migu4zj3pb.cloudfront.net/manuscripts/100000/100035/JCI25100035.pdf.

• Warren, Rob. “Dog Survives Carbon Monoxide Poisoning from House Fire.” School of Veterinary Medicine, 22 May 2024. http://www.vetmed.ucdavis.edu/news/dog-survives-carbon-monoxide-poisoning-house-fire.